Ignition apparatus



cto 8, '3935. l c. H. Dim/ns, JR @916,559

IGNITION APEARATUS Filed Feb. ll, 19342 2 Sheets-Sheet l 06%. 8, 1935. C. H, DAVIS, JR ZQOGS IGNITION APPARATUS Filed Feb. ll, 1952 2 Sheets-Sheet 2 Patented Oct. 8, 1935 UNITED STATES PATENT OFFICE IGNITION APPARATUS Ware Application February 11, 1932, Serial No. 592,289

9 Claims.

This invention relates to ignition timing distributor units for internal combustion engines and particularly for engines having a relatively large number of cylinders or spark gaps and requiring the use of a relatively massive ignition timer cam and distributor rotor.

Some trouble has been experienced with ignition timer distributor units for multi-cylinder engines because upon sudden acceleration of the engine a relatively heavy strain is placed upon the driving connections between the main drive shaft of the timer distributor unit and the cam and distributor rotor. This difficulty is encountered particularly because of the unusual mass of the cam and rotor to be accelerated whenever the engine is suddenly accelerated. It is an object of the present invention to overcome these difficulties by certain improvements in the construction of the driving connections leading to the cam and distributor rotor.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a longitudinal sectional view of an ignition timer distributor unit embodying the present invention.

Fig. 2 is a sectional View on the line 2-2 of Fig. 1.

Fig. 3 is a perspective View of a portion of the driving connection leading to the timer cam and distributor rotor.

Fig. 4 is a plan view of the cam mounted upon the driving member shown in Fig. 3.

Figs. 5 and 6 are plan and side views respectively of a Wedging member by which the driving member shown in Fig. 3 and the cam shown in Fig. 4 are adjustably connected.

Figs. 7, 8 and 9 are plan views of modied `forms of the driving member shown in Fig. 3.

Fig. 10 is a plan View of a ball bearing shown in Fig. 1 and a device for connecting the same with the driving member shown in Fig. 3.

Fig. 11 is a plan view of a cam constructed to cooperate with a modified form of cam wedging device shown in Figs. 14 to 17.

Figs. 12 and 13 are sectional views taken on the lines |2-I2 and I3-I3 of Fig. 11.

Figs. 14 and 15 are plan and side views of a wedging member similar to that shown in Figs. 5 and 6 but modified in form.

Fig. 16 is a view showing a side elevation of a.

wedge and attaching screw, the wedge being shown in section, the section being taken on the line |6-l6 of Fig. 14.

Fig. 17 is a view similar to Fig. 16 but showing the wedge in section on the line I'l-Il of Fig. 14.

Fig. 18 is a plan View of a cam constructed and arranged to cooperate with a third form of wedge shown in Figs. 21 to 24.

Figs. 19 and 20 are sectional views taken on the lines l9-l9 and 20-20 of Fig. 18.

Figs. 21 and 22 are plan and side views respectively of a third form of wedge.

Fig. 23 is a view showing a side elevation of a wedging screw applied to a wedge the screw shown in section taken on the line 23--23 of Fig. 21.

Fig. 24 is a View similar to Fig. 23 showing the wedge in section on line 24-24 of Fig. 2l.

Referring to Fig. l, 2U and 2| designate ignition timer housing member secured together by screws such as shown at 22 thereby enclosing a chamber 23 which receives a centrifugal device for controlling the timing of the ignition. The member 20 provides a tubular shank 24 received by a well in an engine frame which supports the timer. The shank 24 provides a bearing 25 for a shaft 26 carrying a gear 21 which *meshes with a gear driven by the engine. The shaft 26 carries adjacent its upper end a collar 28 which is supported upon a thrust washer 29 bearing against an upper end of a tubular boss 30 which is in effect an extension of the shank 24. The shaft 26 is attached at its upper end to a weight plate 3l which bears against the collar 28 and which is attached by riveting over the annular end portion 32 of the shaft 26, said end portion surrounding an internal bore 33 of the shaft 26. The plate 3| carries studs 35 which pivotally support laminated weights 36 spot Welded together and slidable across ribs 38 formed in the plate 3l. The weights 36 have lever arms 39 cooperating with lever arms 40 of a bar 4l.

Pins 50 secure together the bar 4I, a spacer plate 45 and a weight retainer plate 46 coextensive with the plate 45 and having Wings 41 which are offset from the portion 46 and which extend over the weights 36 to retain them loosely upon the ribs 38. The parts 4I, 45 and 46 have central holes which are aligned when these parts are assembled by the pins 50. The wall of the central hole through this assembly of parts is serrated and then the assembly is hardened and pressed on an unhardened portion 42 of a cam carrying shaft 43 whose lower end portion 44 has a bearing in the internal bore 33 of the shaft 26.

One of the pins 5D is longer than the other and extends into a hole 5| in the weight plate 3|, the hole 5I being of a size such as to provide a means for stopping movement of the pin 5D within a prescribed range of movement. The weights 36 are urged toward the shaft by spring 52 connecting the posts 35 with the posts 50.

The posts 50 are not only connected to the shaft 43 through parts 4|, 45 and 46 having a drive fit therewith, but are directly connected with the shaft 43 by parallel cross-pins 53 driven through holes in the shaft 43. Each end of each pin 53 fits snugly into a groove 54 in each pin 53. In this manner the part 4I which is the driving member for the shaft 43 is securely anchored to the shaft 43 in such a manner that angular displacement cannot occur without disrupting the driving fit between the parts 4 i, 45 and 46 and the shaft part 42 and without also bending the pins 53. This construction is of course useful for ignition apparatus required to rotate in either direction.

The modified form of the part shown in Fig. 3 is shown in Fig. 'I in which one pin 53a, is employed. This pin extends diametrically across the shaft 43 and has its ends bent so as to be received by the grooves 54 in each of the pins 53. Fig. 8 is similar to Fig. with the exception that two pins 53h are employed, these pins 53D have tapered inner ends driven into tapered holes in the `shaft 43.

The form shown in Fig. 9 is adapted for use in a distributor which is required to rotate in one direction only. One cross pin 53e is employed and the ends thereof are received snugly by the groove 54 of pins 50.

The shaft 43 is journaled in a ball bearing 6D received in a cup-shaped part Gl provided in the base of the housing 2|. The inner race of a bearing 60 is retained upon a shoulder 62 of shaft i3 by a resilient C-washer 53 which is shown also in Fig. 10 and which is snapped into a groove G4 provided in the shaft 43. A spacer 65 is located between the washer 65 and the inner race of the bearing 60.

The washer 63 provides a seat for a cam 'Ill having a center bore which nts over the upper end of the shaft 43. The upper end of the shaft 43 is tubular in formation and is slit in order to provide four resilient wedging members 'Il which are adapted to be wedged apart against the inner Wall of the bore of the cam 'I0 in order to tightly secure the cam 1D on the shaft 43 in the desired position of adjustment. The member for wedging apart the prongs 1l is shown in Figs. 5 and 6 and is designated in its entirety by numeral '32. The member 12 is formed to provide a frusto-conical wedging portion 13 from which extends in diametrically opposite directions two lugs 14 which remain after cutting away portions of an annular ange 'I5 with which the wedge 12 was originally provided, said flange 15 being indicated by dotdash lines in Fig. 5. The wedge 12 is provided with a central bore 'i6 to receive a wedge screw 11 whose threaded lower end screws into a hole tapped centrally in the shaft 43. The wedge 'i2 is permanently secured to the screw 17 by deforming the lower end of its conical portion 'i3 as indicated at 'i8 in Fig. 1 into groove i9 provided by the screw 11. The cam 1U is provided with diametrically opposite notches for receiving the lugs 14 of the wedge 12 as shown in Fig. l. These notches 80 are formed in the tubular extension 8| of the cam 1U which extension is provided with flats 82 and 83 which are received by suitably formed apertures in a distributor rotor block 93 in order that the cam 10 may drive the block 9B.

The tightening of the screw 'Il causes the wedge 'l2 to move longitudinally into the shaft 43 thereby urging the prongs 'il tightly against the cam 7D. Since the wedge 'i2 is provided with lugs 14 directly drivingly connected with the cam 'i0 it is apparent that the cam is bound first to the shaft t3 due to friction which exists between the outer surfaces of the prongs 1I and the inner wall of the wall of the cam 'i5 and to friction which exists between the outer conical surfaces 13 of the wedge 12 and the inner conical surfaces of the prongs 1l. In this way a double binding effect is obtained by utilizing both the external and internal surfaces of the prongs 1I.

The cam 'l0 cooperates with a circuit interrupter 85 mounted on a plate 86 supported by the housing member 2l and supporting an ignition condenser 81.

The rotor carries a conducting rotor 9| which carries current from a center button 92 to alternate distributor posts 93. The rotor block 96 carries a conducting rotor 94 for conducting current to alternate distributor posts 93. The conductor S4 is electrically connected with a brush 95 bearing against a conducting ring 96. The button 92 and ring 95 are connected, respectively, with posts 91 and 38 having threaded sockets for receiving threaded connector plugs. not shown.

Referring to Figs. 11 and 17 inclusive, showing a modified form of cam securing device it will be noted that the cam 10 shown in Fig. l1 differs with respect to the cam iii of the first form of the cam by having a portion la of its central bore elliptical in cross-sectional shape so as to cooperate with a wedge Ma having a corresponding elliptical shape. When this wedge 12a is screwed into wedging position the prongs 'il of the shaft 43 will be forced apart into the elliptical bore 10a of the cam 7G. Thus it is seen that an additional holding effect is secured since the cam 7D cannot be angularly displaced with respect to the shaft d3 without skewing the prongs 'Il of the shaft 43.

The wedge i217 in the form of cam wedging device shown in Figs. 19 to 24 omits the lugs 14, and the cam lil shown in Figs. 19 and 20 omits the notches 8G. power due to the additional wedging action due to the difference between the major and minor diameters of the elliptical contour of the wedge, `Said wedging action 'taking place whenever there is a force tending to displace the shaft 43 angularly with respect to the cam 10.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In an ignition timer, the combination comprising, a timer cam for operating a circuit interrupter, a shaft for driving the cam, said shaft having a split internally conical, tubular portion providing wedging prongs adapted to engage the inner Wall of a central bore of the cam, a conical wedge complementary to the internally conical portion of the shaft received between said prongs, a wedge tightening screw passing through a central hole in the wedge and having threaded engagement with said shaft, the head of the screw bearing against the outer end of the wedge, and spline connections between the wedge This form provides great holding and cam to provide a positive driving relation between the Wedge and the cam beyond the end of the shaft.

2. In an ignition timer, the combination comprising, a timer cam for operating a circuit interrupter, a shaft for driving the cam, said shaft having a split internally conical, tubular portion providing wedging prongs adapted to engage the inner wall of a central bore of the cam, a conical wedge received between said prongs, a wedge tightening screw passing through a central hole in the wedge and having threaded engagement with said shaft, the head of the screw bearing against the outer end of the wedge, and transversely extending lugs provided by the wedge and received by notches in said cam to provide a positive driving relation between the wedge and the cam beyond the end of the shaft.

3. In an ignition timer, the combination comprising, a timer cam for operating a circuit interiupter, a shaft for driving the cam, said shaft having a split, internally conical, tubular portion providing wedging prongs' adapted to engage the inner wall of a central bore of the cam, a conical wedge received between said prongs, a wedge tightening screw passing through a central hole in the wedge and having threaded engagement with said shaft, the head of the screw bearing against the outer end of the wedge, the wedge being non-circular in cross-sectional contour and adapted to wedge the prongs against an internal wall of the cam surrounding a portion of the central bore of the cam which is noncircular in cross-sectional contour.

4. In an ignition timer, the combination comprising, a timer cam for operating a circuit interrupter, a shaft for driving the cam, said shaft having a split, internally conical, tubular portion providing wedging prongs adapted to engage the inner wall of a central bore of the cam, a conical wedge received between said prongs, a wedge tightening screw passing through a central hole in the wedge and having threaded engagement with said shaft, the head of the screw bearing against the outer end of the wedge, the wedge being non-circular in cross-sectional contour and adapted to wedge the prongs against an internal wall of the cam surrounding a portion of the central bore of the cam which is noncircular in cross-sectional contour, and spline connections between the wedge and cam to provide a positive driving relation between the wedge and the cam.

5. In a device of the character described, the combination comprising, a shaft having expansible members at one end thereof and adapted to extend into a cam having a reduced portion projecting beyond the end of the shaft, said reduced portion being provided with a plurality recesses;

of notches; a wedge adapted to extend between the expansible member of the shaft for spreading the members; means to urge the wedge in one direction to firmly connect the wedge with the shaft; and means carried by` the wedge and ex- 5 tending into the notches of the reduced portion of the cam beyond the end of the expansible members whereby the cam is driven by the wedge.

6. In an adjusting device for securing a cam in infinite number of positions to the end of a driV- ing shaft having a split tubular portion to provide yieldable members adapted to engage a portion of the inner wall of a central bore of a cam, the combination comprising; a wedge; means operable upon the wedge to cause the yieldable members to bear against the inner walls of the cam; and spline connections between the wedge and the cam located beyond the ends of the yieldable members of the shaft to provide a positive driving relation between the lwedge and the cam.

7. In a device of the character described, the combination comprising; a shaft having an expansible end; acam adapted toI fit over the expansible end; a wedge; means cooperating with the wedge for locking the cam to the shaft; and spline connections between the wedge and the cam located beyond the expansible end of the shaft to provide a positive driving relation between the cam and the wedge.

8. In a device of the character described, the combination with a rotatable cam carrying shaft having an expansible end; of a cam supported on the expansible end; said cam having a plurality of notches; a wedge having keys adapted to t in the notches of the cam beyond the expansible end of the shaft; and means cooperating with the shaft to cause the wedge to expand the end of the shaft to hold the cam in a certain relation with respect to the shaft and to hold the keys within the notches to provide for a positive driving relation between the wedge and the cam.

9. In a device of the character described, the combination with a driving shaft, of an ignition device including a cam carrying element having an expansible shank; of a cam adapted to fit on the shank, said cam having a plurality of a wedge provided with projections adapted to extend into the recesses; and means cooperating with the shaft to force the wedge into the eXpansible shaft to expand the shank thereby locking the cam in a predetermined relation with respect to the cam carrying element and hold the projections within the recesses above the end of the cam carrying element to provide for a positive driving relation between the wedge and the cam.

CHARLES HALL DAVIS, JR. 

